家禽家畜的饲养由过去的自由放养或农产分散饲养逐步过渡到养殖公司工厂化饲养和农村养殖专业户规模化饲养。
The mode of poultry and livestock transforms from feeding freely or feeding separately by farmer in past to factory feeding by breeding company and dimensions feeding by breeding specialization farmer step by step .